JPH1182649A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission which has a very wide variable range owing to a low pollution, a low fuel consumption and a high performance, and can cope with a high output and a large exhaust am ount, and furthermore, applicable to a gas/electric hybrid vehicle. SOLUTION: A planetary gear mechanism 2 which consists of a sun gear 3, plural planetary gears 6, 6, and 6 and a ring gear 15, is provided, the driving shaft 5a of an engine 5 is connected to the sun gear 3, the rotary shaft 13a of a motor 13 is connected to a planetarg gear holder 7A installed with the plural planetary gears 6, 6, and 6, and an output shaft is connected to the ring gear 15, and by controlling the rotation frequency of the motor 13 to the rotation frequency of the engine 5, the gear ratio is changed in a wide range, so as to output advance, backing and stop of the vehicle at this gear ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission that can receive input torque from both an engine and a motor and can be applied as a gasoline / electric hybrid vehicle.

[0002]

2. Description of the Related Art The basic performance required of vehicles including two and four wheels is high power performance and low fuel consumption and low pollution. However, the conventional internal combustion engine burns fuel to obtain an output, so when trying to obtain high power performance,
More fuel needs to be burned, which conflicts with low fuel consumption and low pollution.

[0003] Considering how to efficiently use the output from the engine instead of the engine itself,
Since the output of the engine changes with the engine speed and generates the maximum output at a certain speed, in order to obtain high acceleration performance, always keep the engine speed near the maximum output at the maximum engine speed. You only have to use and drive. Further, low fuel consumption and low pollution means that the smaller the number of combustions per unit time, that is, the lower the number of revolutions of the engine, the smaller the fuel consumption and the amount of exhaust gas.

[0004] It would be good if such an engine could always be used according to the situation.
In a transmission (MT) or an automatic truss transmission (AT), three to five types of gear ratios are manually or automatically selected and traveled, so the engine is accelerated by adjusting the engine speed to one maximum output generating rotational speed. It is impossible to do so, and if you set the engine to the lowest engine speed that maintains the speed during the cruise, you can do all the acceleration without having to shift down each time you want to accelerate next time Absent. Therefore, if a continuously variable transmission is used, at the time of maximum acceleration, the gear ratio is continuously changed according to the increase in vehicle speed, so that the engine can always be accelerated while maintaining the engine speed at the maximum output generating speed. In addition, during cruise driving, the engine speed is reduced to the barely necessary output for cruising, and then when acceleration is required, the required acceleration can be obtained by changing the gear ratio in a timely manner. At a very high level, both "high power performance" and "low fuel consumption and low pollution" can be achieved.

[0005]

However, since the conventional continuously variable transmission is constituted by a combination of a steel belt and a pulley whose circumference changes, there are the following disadvantages. (1) Operation noise, wear, heat generation, between belt and pulley
Horsepower loss occurs. (2) Transmission of high output is difficult due to the durability of the belt. (3) Due to the structure, the range in which the gear ratio can be changed is limited.

Accordingly, the present invention has a very wide variable range for low pollution, low fuel consumption and high performance, can cope with high output and large displacement, and can be used as a gasoline / electric hybrid vehicle. It is an object of the present invention to provide a continuously variable transmission that can be applied.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a planetary gear mechanism including a sun gear, a plurality of planetary gears, and a ring gear, and a driving shaft of an engine mounted on the sun gear. By connecting a rotating shaft of a motor to a planetary gear holder to which the plurality of planetary gears are attached, connecting an output shaft to the ring gear, and controlling the number of rotations of the motor with respect to the number of rotations of the engine, The continuously variable transmission is characterized in that the ratio can be changed over a wide range and the forward, reverse and stop of the vehicle can be output at the gear ratio. Further, a planetary gear mechanism including a sun gear, a plurality of planetary gears and a ring gear is provided, a rotation shaft of a motor is connected to the sun gear, and a drive shaft of an engine is connected to a planetary gear holder to which the plurality of planetary gears are attached, By connecting an output shaft to a ring gear and controlling the number of revolutions of the motor with respect to the number of revolutions of the engine, the gear ratio can be changed over a wide range, and the forward, reverse and stop of the vehicle can be output at the gear ratio. It features a continuously variable transmission.

[0008] Further, the continuously variable transmission is characterized in that the motor also has a function of a generator.
Further, a continuously variable transmission is characterized in that a transmission gear is interposed between the rotation shaft of the motor and the planetary gear holder or between the rotation shaft of the motor and the sun gear. A continuously variable transmission is characterized in that the motor speed is controlled with respect to the engine speed in accordance with the accelerator opening and the vehicle speed signal of the vehicle.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a continuously variable transmission according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a continuously variable transmission according to the present invention, FIG. 2 is a side sectional view of a planetary gear mechanism portion of the continuously variable transmission shown in FIG. 1, and FIG. 3 is a planetary gear of the continuously variable transmission shown in FIG. FIG. 4 is an exploded perspective view of the gear mechanism, FIG. 4 is a schematic front view of the planetary gear mechanism, and FIG. 5 is an enlarged schematic view of the planetary gear mechanism.

As shown in FIGS. 1 to 4, the continuously variable transmission 1 has a planetary gear mechanism 2. The sun gear 3 of the planetary gear mechanism 2 includes a drive shaft 5 of the engine 5.
a are connected. Planet gears 6, 6, and 6 mesh with the sun gear 3, and the planet gears 6, 6, and 6 are provided with collars 10, 10, and 10 at pins 8, 8, and 8 protruding from a circular planet gear holder 7A. It is rotatably supported via. Further, a planetary gear holder 7B having a substantially triangular shape in a front view is attached to the tips of the pins 8, 8, 8 (see FIG. 3), and nuts 12, which are screwed to the tips of the pins 8, 8, 8 are fitted. 1
It is stopped at 2,12. That is, the planetary gears 6, 6, and 6 are mounted on the planetary gear holders 7A and 7B, and revolve around the sun gear 3 integrally.

An end of the drive shaft 5a of the engine 5 connected to the sun gear 3 is rotatably inserted into substantially half of the center hole of the planetary gear holder 7A on the planetary gear side. The tip of the rotating shaft 13a of the motor 13 is fitted and fixed to the other approximately half.
That is, the planetary gear holder 7 </ b> A
The motor 13 is rotatable with respect to a and rotates together with the rotating shaft 13a of the motor 13.

The planetary gears 6, 6, and 6 are ring gears 1.
5, and sun gear 3, planetary gears 6, 6, 6
The ring gear 15 constitutes the planetary gear mechanism 2. The ring gear 15 is mounted on a ring-shaped ring gear holder 16A.
Is fixed to a circular ring gear holder 16B, and an output gear 17 is fixed to the ring gear holder 16B. That is, the ring gear 15, the ring gear holders 16A and 16B, and the output gear 17 rotate integrally.

A hole is made in the center of the ring gear holder 16B and the output gear 17, and a drive shaft 5a of the engine 5 is rotatably inserted into the center hole. 2, reference numerals 18 and 19 denote drive shafts 5a for preventing the ring gear holder 16B and the output gear 17 from moving in the axial direction with respect to the drive shaft 5a of the engine 5.
The disk is fixed to the Further, the rotation of the ring gear 15 is transmitted to the differential gear 20 via the ring gear holders 16A and 16B and the output gear 17, and rotates the left and right axles 21 and 22.

As shown in FIG. 1, electricity generated by an AC generator 25 directly connected to the engine 5 is charged to a battery 27 via a control device 26, and
The electricity charged in 7 is supplied to the motor 13 via the control device 26. Electricity generated by the motor 13 during braking is charged to the battery 27 via the control device 26.
The signal 28 of the accelerator opening and the vehicle speed is transmitted to the control device 2.
6 and is processed to control the rotation speed of the motor 13 with respect to the rotation speed of the engine 5.

Next, the operation of the continuously variable transmission configured as described above will be described with reference to FIG. If motor rotation (revolution of planetary gear 6) = gear ratio × engine rotation (rotation of sun gear 3), ring gear 15 does not rotate. If motor rotation (revolution of planetary gear)> gear ratio × engine rotation (rotation of sun gear), the ring gear rotates clockwise. If motor rotation (revolution of planetary gear) <gear ratio × engine rotation (rotation of sun gear), the ring gear rotates counterclockwise.

Here, the radius of the sun gear 3 of the continuously variable transmission 1 is a, the radius of the planetary gear 6 is b, the number of revolutions of the sun gear 3 is Na, the number of revolutions of the planetary gear 6 is nb, and the number of revolutions of the ring gear 15 is Is Nc, the following relational expression holds. [Case 1] Assuming that the number of revolutions Nc of the ring gear is 0 and the number of revolutions (number of revolutions) Nb of the planetary gear is 1, the number of revolutions nb of the planetary gear is 2πb / 2π (a + 2b) = b /
(A + 2b). Therefore, the rotation speed of the sun gear Na
Is (2πb / 2πa) × the number of revolutions of the planetary gear Nb + the number of revolutions of the planetary gear nb = (2πb / 2πa) × 1 + b / (a + 2b) = (b / a) × 1 + b / (a + 2b) = ｛2b (a + b) ｝ / {A (a + 2b)}.

[Case 2] Set the ring gear rotation speed Nc to 0.
Assuming that the number of rotations of the planetary gear is Nb, the number of revolutions nb of the planetary gear is {2πb / 2π (a + 2b)} × Nb =
{B / (a + 2b)} × Nb. Therefore, the rotation number Na of the sun gear is (2πb / 2πa) × the number of rotations Nb of the planetary gear + the number of revolutions nb of the planetary gear = (2πb / 2πa) × Nb + {b / (a + 2b)} × Nb = (b / a) × Nb + {b / (a + 2b)} × Nb = {2b (a + b)} / {a (a + 2b)} × Nb

[Case 3] Assuming that the number of revolutions of the ring gear is Nc and the number of revolutions of the planetary gear is Nb, the number of revolutions nb of the planetary gear is {2πb / 2π (a + 2b)} × Nb + N.
c = {b / (a + 2b)} × Nb + Nc. Therefore, the rotation number Na of the sun gear is (2πb / 2πa) × the number of rotations Nb of the planetary gear + the number of revolutions nb of the planetary gear = (2πb / 2πa) × Nb + {b / (a + 2b)} × Nb + Nc = (b / a) × Nb + {b / (a + 2b)} × Nb + Nc = {2b (a + b)} / {a (a + 2b)} × Nb + Nc

Therefore, the relationship between the sun gear rotation speed Na, the planetary gear revolution number nb, and the ring gear rotation speed Nc can be expressed by the following equation. Nc = {2 (a + b) × nb−a × Na} / (a + 2
b) Based on this formula, the rotation speed Na of the sun gear 3 by the engine 5 is 1000 rpm, the revolution number nb of the planet gear 6 by the motor 8 is 100 to 2000 rpm, and the radius ratio of the sun gear 3 and the planet gear 6 is 0.5 to 2 When the rotation speed Nc of the ring gear 15, which is the output rotation, is simulated on the assumption that the rotation speed is 0.0, the results are as shown in FIGS.

For example, as shown in FIG. 7, when the radius ratio of the sun gear radius a to the planet gear radius b is 1.0, the rotation speed Na of the sun gear 3 by the engine 5 is 1000 rpm.
And the number of revolutions nb of the planetary gears by the motor 8 is 2000r.
pm, the rotation speed Nc of the ring gear 15 is 2333.
rpm, and the number of revolutions nb of the planetary gear is 1000r.
pm, the rotation speed Nc of the ring gear is 1000 rpm
m, and the number of revolutions nb of the planetary gear is 300 rpm, the number of revolutions Nc of the ring gear is 67 rpm,
By adjusting the motor speed relative to the engine speed, a very wide range of gear ratios can be obtained,
In addition, the speed can be changed smoothly without any step.

The number of revolutions nb of the planetary gear is set to 250 rpm.
m, the number of revolutions Nc of the ring gear becomes 0,
Power can be transmitted or cut off without a clutch mechanism, and a clutchless system can be realized. Further, if the number of revolutions nb of the planetary gear is set to 250 rpm or less, the ring gear rotates in the reverse direction, so that the configuration of the reverse gear becomes unnecessary. 6, 7 and 8, the rotation speed Na of the sun gear 3 by the engine 5 is set to 1000 rpm.
However, the present invention is not limited to this, and it is a matter of course that other various rotational speeds may be used.

Therefore, since the power transmission system is entirely constituted by gears, there is less wear, heat generation and horsepower loss due to the belt compared to the belt-pulley transmission type continuously variable transmission, which can be kept at the level of the existing manual transmission. be able to. In addition, since the power transmission system is entirely composed of gears, the belt does not break due to high output, and it is possible to cope with a high-output engine. Further, since the gear ratio can be made infinite, a clutch and a torque converter mechanism are not required.

As shown in FIG. 1, when an accelerator opening and a vehicle speed signal 28 are input to the control device 26, the control device 26 controls the motor 13 to an optimum rotation speed with respect to the rotation speed of the engine 5. It is supposed to. In addition, since hybrid traveling by the engine 5 and the motor 13 is possible,
When there is room for the charge amount of the battery 27 and the power generation amount of the AC generator 25, the control device 26 can reduce the output of the engine 5 and mainly run the power of the motor 13. In addition, when the vehicle is decelerated, the motor 13 acts as an electric brake, that is, operates as a generator, and the generated electricity is charged into the battery 27 via the control device 26 to recover energy. Also,
When the vehicle starts moving, the engine 5 is mainly operated, and the vehicle can be rapidly accelerated like a normal gasoline-powered vehicle, so that the enjoyment of driving of the gasoline-powered vehicle can be enjoyed.

Next, another embodiment of the continuously variable transmission according to the present invention will be described with reference to FIG. The continuously variable transmission 31 shown in FIG. 9 connects the rotation shaft 13a of the motor 13 to the sun gear 3 of the continuously variable transmission 1 shown in FIG. 1, and connects the drive shaft 5a of the engine 5 to the planetary gear holder 7A. The other configuration is the same as that of the continuously variable transmission 1 described above, so that the same effects as those of the continuously variable transmission shown in FIG. 1 can be obtained.

In the above embodiment, the drive shaft 5a of the engine 5 is connected to the sun gear, and the rotation shaft 13a of the motor 13 is connected to the planetary gear holder, or the rotation shaft 13a of the motor 13 is connected to the sun gear. Although the drive shaft 5a of the engine 5 is connected to the planetary gear holder, the invention is not limited to this. A transmission gear may be interposed between the rotation shaft 13a of the motor 13 and the planetary gear holder or the sun gear.
A transmission gear may be interposed between the drive shaft 5a of the engine 5 and the sun gear or the planetary gear holder.

[0026]

As described above, according to the present invention,
Since the power transmission system is entirely composed of gears, belt wear, heat generation and horsepower loss are less than those of belt-pulley transmission type continuously variable transmissions, and can be kept at the level of existing manual transmissions . In addition, since the power transmission system is composed entirely of gears, the belt does not break due to high output,
It is also possible to support high-power engines. Also, by adjusting the number of revolutions of the engine and motor,
A very wide range of gear ratios can be obtained, and forward, reverse and stop of the vehicle can all be output at the same gear ratio, so that clutches and torque converter mechanisms are not required. Furthermore,
Since the gear ratio can be negative, the ring gear can be rotated in the opposite direction, that is, the vehicle can be retracted,
The configuration of the reverse gear becomes unnecessary.

In addition, the motor can be controlled to an optimum rotation speed with respect to the rotation speed of the engine according to the accelerator opening and the vehicle speed signal of the vehicle, so that efficient traveling is possible. In addition, since hybrid traveling by the engine and the motor is possible, when there is enough charge in the battery, the output of the engine can be reduced and the power of the motor can be mainly traveled. Further, at the time of deceleration, the motor can be operated as a generator to recover energy. Further, by arranging the motor and the planetary gear mechanism in series at the current transmission position, the continuously variable transmission according to the present invention can be mounted without significantly changing the existing vehicle body layout.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a continuously variable transmission according to the present invention.

FIG. 2 is a side sectional view of a planetary gear mechanism portion of the continuously variable transmission shown in FIG.

FIG. 3 is an exploded perspective view of a planetary gear mechanism of the continuously variable transmission shown in FIG.

FIG. 4 is a schematic front view of a planetary gear mechanism.

FIG. 5 is an enlarged schematic view of a planetary gear mechanism.

FIG. 6 is a diagram showing an output rotation of the ring gear, assuming that the rotation speed Na of the sun gear is 1000 rpm, the revolution number nb of the planetary gear is 100 to 2000 rpm, and the radius ratio of the sun gear and the planetary gear is 0.5 and 0.75. It is the figure which simulated rotation speed Nc.

FIG. 7: Assuming that the rotation speed Na of the sun gear is 1000 rpm, the revolution number nb of the planetary gear is 100 to 2000 rpm, and the radius ratio of the sun gear and the planetary gear is 1.0 and 1.25, the output rotation of the ring gear is It is the figure which simulated rotation speed Nc.

FIG. 8 is a diagram showing an output rotation of the ring gear, assuming that the rotation speed Na of the sun gear is 1000 rpm, the revolution number nb of the planet gear is 100 to 2,000 rpm, and the radius ratio of the sun gear and the planet gear is 1.5 and 2.0. It is the figure which simulated rotation speed Nc.

FIG. 9 is a configuration diagram showing another embodiment of the continuously variable transmission according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 continuously variable transmission 2 planetary gear mechanism 3 sun gear 5 engine 5a engine drive shaft 6,6,6 planetary gear 7A planetary gear holder 7B planetary gear holder 8 pin 13 motor 13a motor rotation axis 15 ring gear 16A ring gear holder 16B ring gear Holder 17 Output gear 20 Differential gear 25 AC generator 26 Control device 27 Battery 28 Accelerator opening and vehicle speed signal 31 Continuously variable transmission

Claims (5)

[Claims] A planetary gear mechanism comprising a sun gear, a plurality of planetary gears and a ring gear is provided, a drive shaft of an engine is connected to the sun gear, and a rotary shaft of a motor is connected to a planetary gear holder on which the plurality of planetary gears are mounted. By connecting an output shaft to the ring gear and controlling the number of rotations of the motor with respect to the number of rotations of the engine, the gear ratio can be changed over a wide range, and the forward, backward and stop of the vehicle can be output at the gear ratio. Continuously variable transmission. 2. A planetary gear mechanism comprising a sun gear, a plurality of planetary gears and a ring gear is provided, a rotation shaft of a motor is connected to the sun gear, and an engine drive shaft is connected to a planetary gear holder on which the plurality of planetary gears are mounted. By connecting an output shaft to the ring gear and controlling the number of rotations of the motor with respect to the number of rotations of the engine, the gear ratio can be changed over a wide range, and the forward, backward and stop of the vehicle can be output at the gear ratio. Continuously variable transmission. 3. The continuously variable transmission according to claim 1, wherein the motor has a function of a generator. 4. A transmission gear interposed between a rotation shaft of the motor and the planetary gear holder or between a rotation shaft of the motor and the sun gear. The continuously variable transmission described. 5. The motor according to claim 1, wherein the motor speed relative to the engine speed is controlled in accordance with an accelerator opening and a vehicle speed signal of the vehicle. Continuously variable transmission.